1. Field of the Invention
The present invention relates to plasma displays, and more particularly, to a plasma display in which vertical crosstalk between pixels is suppressed without adversely affecting wall charges of electrodes.
2. Description of the Related Art
A plasma display includes a front plate and a rear plate sealed together and having a space therebetween filled with a dischargeable gas. The front plate includes horizontal rows of electrodes, each row being configured with a sustain electrode in parallel with a scan electrode. The scan electrodes and the sustain electrodes are covered by a dielectric layer and a magnesium oxide (MgO) layer. The back plate supports vertical barrier ribs and vertical column electrodes. In a color display, individual column electrodes are covered with red, green, or blue (RGB) phosphors. A pixel is defined as an area proximate to an intersection of (i) a scan electrode and a sustain electrode, and (ii) three column electrodes for colors red, green, and blue, respectively. A subpixel corresponds to an intersection of a red, green or blue column electrode with an electrode pair of a sustain electrode and a scan electrode.
The scan electrodes are driven individually in an addressing period in which each row may be selected such that sub-pixels along that row may be addressed via an addressing discharge triggered by the application of a data voltage on a vertical column electrode. During a sustain period, a common sustain pulse is applied to all scan electrodes to repetitively generate plasma discharges at each sub-pixel site addressed during the addressing period.
The sustain electrodes provide a reference point for the scan electrodes during the addressing operation. During the sustain period, a common sustain pulse is applied to all sustain electrodes out of phase with the sustain pulses applied to the scan electrodes, such that plasma discharges alternate direction between sustain and scan electrodes.
There are plasma displays in which pairs of sustain electrodes are interdigitated with pairs of scan electrodes. In one example, the electrodes are arranged in a sequence of:                row 1, sustain electrode;        row 1, scan electrode;        row 2, scan electrode;        row 2, sustain electrode;        row 3, sustain electrode;        row 3, scan electrode;        row 4, scan electrode;        row 4, sustain electrode;        etc.Thus, the scan electrodes of rows 1 and 2 form a first pair of scan electrodes, and the scan electrodes of rows 3 and 4 form a second pair of scan electrodes. The sustain electrodes of rows 2 and 3 form a pair of sustain electrodes that is interdigitated with the first and second pairs of scan electrodes.        
The interdigitation of the pairs of electrodes results in a lower inter-electrode capacitance as compared to non-interdigitated electrodes. The lower inter-electrode capacitance is of benefit in a large area plasma display.
An interpixel gap is a region of space between adjacent pixels. In a case where an interpixel gap spacing is made small, a common potential present on a pair of electrodes can result in an erroneous crosstalk discharge and/or wall charge leakage in a neighboring pixel site, particularly in a vertical dimension. Note that for interdigitated pairs of electrodes, as described above, some interpixel gaps fall between adjacent scan electrodes, and some interpixel gaps fall between adjacent sustain electrodes.
A sustain gap is a region of space between a scan electrode and a sustain electrode within which the discharge occurs. A positively charged electrode serves as an anode and a negatively charged electrode serves as a cathode. When a sufficient voltage is applied across the sustain gap, the gas will break down and form a discharge plasma. The discharge plasma has two distinct regions, namely a positive column and a negative glow. The positive column is predominantly composed of fast moving electrons seeking a positive charge on the surface of the anode electrode. Conversely, the negative glow contains slow moving ions drifting toward and across the negatively charged cathode electrode. The duration of the discharge is limited by the amount of charge on the dielectric surfaces of the electrodes.
Each scan electrode is driven by an independently addressable scan driver. During an addressing period for a pixel, the scan driver for the pixel's scan electrode outputs a row select pulse that is coincident with a data pulse being applied to a column electrode of the pixel. Consequently, an address discharge occurs between the pixel's scan electrode and sustain electrode. The address discharge produces a positive column region that can spread across an interpixel gap that separates sustain electrodes, and produces a negative glow region that can reduce the wall charge on the adjacent scan electrode across an interpixel gap that separates a scan electrode pair.
U.S. patent application Ser. No. 10/305,560 describes a technique of vertical crosstalk suppression coupled with interlaced addressing that minimizes positive column crosstalk. However, when the interlaced addressing addresses at a first scan electrode in a scan electrode pair, some wall charge leakage occurs at the discharge site of the second scan electrode in the scan electrode pair, thus reducing the wall charge of the second scan electrode. More specifically, the slow moving negative glow portion of the address discharge spreads across the first scan electrode and has a tendency to deplete the wall charge on the second scan electrode. Subsequently, when the second scan electrode is addressed, the reduced wall charge requires a higher addressing voltage that would have been required had the wall charge not been reduced. The higher addressing voltage is undesirable because power dissipation is proportional to the square of the voltage, and positive column crosstalk is more likely to occur at higher addressing voltages.